Gas Turbine Engine With Inlet Particle Separator and Thermal Management

ABSTRACT

A gas turbine engine includes a nose cone at an inlet end, and spaced radially inwardly of a nacelle. A compressor is downstream of the nose cone. A core inlet delivers air downstream of the nose cone into the compressor. An inlet particle separator includes a manifold for delivering air radially outwardly of the core inlet. Air delivered by the inlet particle separator passes over a heat exchanger before passing to an outlet.

BACKGROUND OF THE INVENTION

This application relates to a gas turbine engine, wherein an inlet particle separator provides a thermal management function.

Gas turbine engines are known, and include a compressor compressing air and delivering it into a combustor section. The air is mixed with fuel in the combustor and ignited. Products of the combustion pass downstream over turbine rotors driving them to rotate.

One type of gas turbine engine is a contra-rotating turbo prop gas turbine engine. In such a gas turbine engine, air may be delivered into a compressor section, as mentioned above from an inlet. The air may include impurities and, thus, it is known to include an inlet particle separator which will tend to force dirt or other impurities radially outwardly, such that clean air is delivered into the compression section.

Recently, the efficiency of gas turbine engines has become of increasing importance. Thus, the loss of air associated with the inlet particle separator, with no achieved benefit, hurts the efficiency of the overall engine.

SUMMARY OF THE INVENTION

In a featured embodiment, a gas turbine engine has a nose cone at an inlet end spaced radially inwardly of a nacelle. A compressor is downstream of the nose cone. A core inlet delivers air downstream of the nose cone into the compressor. An inlet particle separator includes a manifold for delivering air radially outwardly of the core inlet. The air is delivered by the inlet particle separator passing over a heat exchanger before passing to an outlet.

In another embodiment according to the previous embodiment, the heat exchanger cools oil associated with a gear reduction on the gas turbine engine.

In another embodiment according to any of the previous embodiments, the compressor rotates about a central axis of the engine. The nose cone has a radially outermost portion which is radially outward of a radially inner end of the core inlet, such that air having heavier particles is generally directed radially outwardly of the core inlet and into the inlet particle separator.

In another embodiment according to any of the previous embodiments, the manifold extends for 360 degrees about the axis of rotation.

In another embodiment according to any of the previous embodiments, the manifold has an open inlet at an upstream end, and a downstream outlet over a limited portion of the 360 degrees of the circumferentially extending portion.

In another embodiment according to any of the previous embodiments, an ejector is positioned downstream of the heat exchanger for selectively driving air across the heat exchanger.

In another embodiment according to any of the previous embodiments, a turbine section is downstream of the compressor and drives propellers.

These and other features of this application will be best understood from the following specification and drawings, the following of which is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows a gas turbine engine incorporating an inlet particle separator.

FIG. 2 is a detail of the inlet end of the gas turbine engine.

FIG. 3A shows an inlet particle separator.

FIG. 3B is another view of the inlet particle separator.

DETAILED DESCRIPTION

A gas turbine engine 20 is illustrated in FIG. 1 having a nose cone 22 at an inlet end. Nose cone 22 is positioned radially inwardly of a nacelle 24. As shown, air passing the nose cone 22 may enter an inlet 50 of a manifold 28 and be directed across a heat exchanger 32. The heat exchanger 32 may be associated with cooling any fluid on the engine. As one example, the heat exchanger 32 may cool oil which is delivered to a gear reduction associated with the gas turbine engine 20.

Downstream of the heat exchanger 32 the air passes through the ejector 31. The ejector 31 is provided with a control 90 which selectively shoots air into the ejector 31 when the gas turbine engine 20 is on the ground, as there will not be ram air delivered into the inlet when an aircraft associated with the gas turbine engine 20 is not moving. An outlet 30 is downstream of the ejector 31.

The nose cone 22 is designed to ensure the dirtier air will be delivered into the inlet 50, and the clean air passes into a path into a core inlet 26. Core inlet 26 feeds air into a compressor section 27, where it is compressed and delivered into a combustor section 25. The air is mixed with fuel and ignited, and products of this combustion pass downstream over turbine rotors 23, driving them to rotate. The engine 20 may be a contra-rotating prop aircraft with a pair of propellers 80 and 82 rotating in opposed directions. The propellers 80 and 82 are driven by the output shaft of a fan drive gear system 200, which in turn is powered by the turbine section 23. Of course, other engine types may benefit from this disclosure.

FIG. 2 shows a detail of the nose cone 22. Nose cone 22 is shaped such that it has the highest or most radially outward point 100 which is radially further outward than an inner point 101 of a manifold 102 leading into the compressor 27. As is known, the gas turbine engine rotates upon an axis x (FIG. 1) and the “radially outward” position is relative to the axis x. Of course, some impurities or dirt may still be delivered into the core inlet 26. However, due to the shape and positioning of the structure, the heavier particles containing impurities are generally directed radially outwardly of the core inlet 26, and into the inlet 50 of the manifold 28. That is, the majority of the impurities will be passed into the manifold 28, compared to what is passed into the core inlet 26.

As shown in FIG. 3A, the manifold 28 includes a circumferentially extending portion 31 which surrounds a circumference of gas turbine engine 20 for 360 degrees about axis x. The inlet end 50 is not shown, but is generally open (see FIG. 2), while the downstream end is closed as illustrated in this Figure. The circumferentially extending portion feeds into a circumferentially limited outlet 29 which passes air across the heat exchanger 32. FIG. 3B shows another view of the same structure.

The present invention now utilizes the inlet particle separator to perform a thermal management function and, thus, the efficiency of the overall operation of the gas turbine engine is improved.

Although an embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention. 

1. A gas turbine engine comprising: a nose cone at an inlet end, and spaced radially inwardly of a nacelle; a compressor downstream of said nose cone, and a core inlet for delivering air downstream of said nose cone into said compressor; and an inlet particle separator including a manifold for delivering air radially outwardly of said core inlet, said air delivered by the inlet particle separator passing over a heat exchanger before passing to an outlet.
 2. The gas turbine engine as set forth in claim 1, wherein said heat exchanger cools oil associated with a gear reduction on the gas turbine engine.
 3. The gas turbine engine as set forth in claim 1 wherein said compressor rotating about a central axis of the engine, and said nose cone has a radially outermost portion which is radially outward of a radially inner end of said core inlet, and such that air having heavier particles is generally directed radially outwardly of said core inlet and into said inlet particle separator.
 4. The gas turbine engine as set forth in claim 1, wherein said manifold extends for 360 degrees about said axis of rotation.
 5. The gas turbine engine set forth in claim 4, wherein said manifold having an open inlet at an upstream end, and a downstream outlet over a limited portion of the 360 degrees of the circumferentially extending portion.
 6. The gas turbine engine as set forth in claim 1, wherein an ejector is positioned downstream of said heat exchanger, said ejector for selectively driving air across the heat exchanger.
 7. The gas turbine engine as set forth in claim 1, wherein a turbine section is downstream of said compressor and drives propellers. 